The present invention relates to improvements in mobile phones which have system connectors to permit auxiliary components to be connected to them.
Mobile phones have become popular in recent years because they free the user from fixed communications networks. The user is not required to wait at the home or office for an anticipated call. Instead, the call can be forwarded to the user at whatever location the user happens to be.
A wide variety of phone accessories are available to enhance the usefulness of mobile phone. Common accessories for mobile phones include hand sets, vibrators, speech recognition units, hands-free kits for vehicles, and battery chargers. Typically, the phone accessories plug into a system connector on the body of the telephone to connect the electrical circuit within the accessory to the circuit inside the telephone. Telephones manufactured by Ericsson, Inc., for example, have a class of such accessories known generally as "Ericsson Accessories" which can be connected using the phone's existing system connector.
It is also known to use the telephone as a transmission medium for a connected computer to enable the user to send and receive data and fax communications. One approach used in the past is to connect the phone to an external modem or modem equipped computer. This approach uses the mobile phone merely for transmission of signals that are modulated by the modem in the computer. For example, some phones implement a PC card form factor to provide data/fax functionality for a mobile computer equipped with a PC card slot. However, the PC card adds an additional expense for users that want data/fax functionality.
Another approach is to incorporate an internal modem into the mobile phone and provide an interface for accessing the phone's internal modem using a computer or other external device. This approach can be implemented using a dedicated port on the phone or the phone's built-in system connector for communications with the external device. For example, some phones use an infrared data port for communications with the external device. In the past, phones adopting this approach have required that special protocol drivers be installed in the external device in order to operate properly. Thus, the manufacturer was required to write and distribute drivers for many different operating systems such as Windows 3.1, Windows 95, Windows 98, Palm Pilot, Windows CE, etc. Moreover, if the user installs a new operating system, there is no guarantee that the driver will operate. Thus, the user may be required to obtain and install a new infrared driver when a new operating system is installed.
Another drawback to using a dedicated port for communications with an external device, is that the dedicated port requires additional space and adds to the cost of the phone. In particular, the use of a separate infrared data port requires a separate transmitter in the phone and significantly increases its cost and weight.
Accordingly, it would be preferable to have a telephone design in which a single system connector could be used to connect accessories as well as computing devices, without the need to provide additional drivers for the mobile computer to properly operate with the telephone.